An inflatable vehicle occupant protection device, such as an air bag, is part of an apparatus which further includes a crash sensor and an inflator. The crash sensor senses vehicle conditions that indicate the occurrence of a crash. When the crash sensor senses a crash-indicating condition of at least a predetermined threshold level, the inflator is actuated. The inflator then emits inflation fluid which inflates the air bag into the vehicle occupant compartment to help restrain movement of an occupant of the vehicle.
The air bag and the inflator are installed together at a location in the vehicle adjacent to the vehicle occupant compartment. For example, a driver's side air bag and inflator may be located on the vehicle steering column. A passenger side air bag and inflator may be located in the vehicle instrument panel.
In addition to the air bag and the inflator, the apparatus typically includes a reaction structure and a retainer. The reaction structure supports the inflator and the air bag at the installed location in the vehicle. The retainer typically comprises a circular ring or a rectangular frame surrounding the inflator. An edge portion of the air bag also surrounds the inflator. A plurality of fasteners clamp the edge portion of the air bag between the retainer and the reaction structure. When the inflation fluid emitted from the inflator flows into the air bag to inflate the air bag, the force of the inflation fluid pressure tends to pull the edge portion of the air bag outward from between the retainer and the reaction structure.